diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/lib/qspinlock.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/powerpc/lib/qspinlock.c b/arch/powerpc/lib/qspinlock.c index 6dd2f46bd3ef..8830267789c9 100644 --- a/arch/powerpc/lib/qspinlock.c +++ b/arch/powerpc/lib/qspinlock.c @@ -715,7 +715,15 @@ again: } release: - qnodesp->count--; /* release the node */ + /* + * Clear the lock before releasing the node, as another CPU might see stale + * values if an interrupt occurs after we increment qnodesp->count + * but before node->lock is initialized. The barrier ensures that + * there are no further stores to the node after it has been released. + */ + node->lock = NULL; + barrier(); + qnodesp->count--; } void queued_spin_lock_slowpath(struct qspinlock *lock) |